[tex]\frac{2x-4}{x+1}=\frac{2x+2-6}{x+1}=\frac{2x+2}{x+1}-\frac{6}{x+1}=2-\frac{6}{x+1}[/tex]
[tex]2\in\mathbb{Z}\Rightarrow\frac{6}{x+1}\in\mathbb{Z}\Rightarrow x+1\mid6[/tex]
[tex]x+1\in\{1,2,3,6,-1,-2,-3,-6\}[/tex]
[tex]x\in\{0,1,2,5,-2,-3,-4,-7\}[/tex]
[tex]A=\{0,1,2,5,-2,-3,-4,-7\}[/tex]
[tex]A\cap N=\{0,1,2,5\}[/tex]
